Resilient coupling

ABSTRACT

Couplings are provided which are designed primarily to be used between the propeller shaft and the engine shaft of a boat. The coupling embodies rings of rigid and resilient material alternately arranged, with the rings of resilient material maintained under compression by means of screw bolts or cap screws. The coupling insulates the shafts from each other electrically, to eliminate electrolytic action, and, at the same time, absorbs a certain amount of vibration and misalignment. The design, moreover, is such that at no time is the resilient material under tension or stretch, but, rather, any deflection of the coupling about its axis tends to compress the resilient material.

United States Patent l 72] Inventor William B. Herbert H] Yantacaw Brook Rd., Montclair, N .J

07043 [2| Appl. No. 29,905 [22] Filed Apr. 20, 1970 [45] Patented Sept. 7, 1971 [54] RESILIENT COUPLING 12 Claims, 1] Drawing Figs.

[52] U.S.Cl 64/13 [51] Int. Cl Fl6d 3/78 [50] Field of Search 64/9, l3, 14, l l,27;287/l92 [56] References Cited UNITED STATES PA'll-IN'I'S 2,331,781 Hl/l943 Hollander 64/13 2,639,595 5/1953 Werner ()4/l 3 l,947,()52 2/l934 Lack 64/13 FOREIGN PATENTS 622,147 4/1949 Great Britain Primary Examiner-Kenneth W. Sprague Att0rneylsler and Ornstein ABSTRACT: Couplings are provided which are designed primarily to be used between the propeller shaft and the engine shaft of a boat. The coupling embodies rings of rigid and resilient material alternately arranged, with the rings of resilient material maintained under compression by means of screw bolts or cap screws. The coupling insulates the shafts from each other electrically, to eliminate electrolytic action, and, at the same time, absorbs a certain amount of vibration and misalignment. The design. moreover, is such that at no time is the resilient material under tension or stretch, but, rather, any deflection of the coupling about its axis tends to compress the resilient material.

PATENTEUSEP 7x971 3.603; 108

' SHEET 1 0F 4 Fig.

IN VENTOR.

WILLIAM B. HERBERT ATTORN EYS SHEET 2 OF 4 Fig. 4

43 42 55 54 56 o 42 44 JJ 40 54 53 54 Fly. 5

INVENTOR.

WILLIAM B. HERBERT BY (LA/V 9W ATTORNEYS PATENTEDSEP Hen (SL603; 108

sum 3 OF 4 Fig. 7

Fig. 9

INVENTOR. WILLIAM B. HERBERT MA QWM ATTORNEYS PATH-HEB SE? 7 I971 SHEET t 0F 4 INVENTOR.

WILLflAM B. HERBERT ATTORNEYS RESILIENT COUPLING This invention relates to a resilient coupling, but has reference more particularly to a coupling of this character which is particularly adapted for use between the propeller shaft and engine of a boat.

A primary object of the invention is to provide a coupling of the character described, which insulates one shaft from the other electrically, whereby, when the coupling is used in the marine field, the possibility of electrolysis or electrolytic action is eliminated.

' Another object of the invention is to provide a coupling of the character described, which is sufficiently resilient to effectively absorb a certain amount of vibration and misalignment.

A still further object of the invention is to provide a coupling of the character described, in which the resilient material is at no time under tension or stretch, but, rather, any deflection of the coupling about its axis tends to compress the resilient material.

Other objects and advantages of my invention will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification, and in which like numerals are employed to designate like parts throughout the same,

FIG. 1 is a fragmentary view, partly in elevation and partly in section, of a preferred form of coupling embodying the invention;

FIG. 2 is an elevational view of one of the rigid rings or members of the coupling shown in FIG. 1;

FIG. 3 is an elevational view of one of the resilient rings or members of the coupling shown in FIG. 1;

FIG. 4 is a view similar to FIG. 1, but showing a modified form of coupling;

FIG. 5 is an elevational view of one of the rigid rings or members of the coupling shown in FIG. 4;

FIG. 6 is an elevational view of one of the resilient rings or members of the coupling shown in FIG. 4;

FIG. 7 is a view similar to FIG. 1, but showing another modified form of coupling;

FIG. 8 is an elevational view of one of the rigid rings or members of the coupling shown in FIG. 7;

FIG. 9 is an elevational view of one of the resilient rings or members of the coupling shown in FIG. 7;

FIG. 10 is a view similar to FIG. 1, but showing a modified form of one of the flanges used in the coupling, and

FIG. 11 is a cross-sectional view, taken on the line 11-11 of FIG. 10.

Referring more particularly to FIGS. 1 and 3 inclusive of the drawings, the coupling is shown as interposed between a shaft 1, which may be a propeller shaft in a boat, and a shaft 2, which may be the engine shaft.

The shaft 1 has rigidly secured thereto a collar 3 having a flange 4, and the shaft 2 has secured thereto a similar collar 5 having a flange 6. The flange 4 is provided adjacent its periphery with a series of uniformly and circumferentially spaced holes 7, and the flange 6 is similarly provided adjacent its periphery with a series of uniformly and circumferentially spaced holes 8, which are in axial alignment with the holes 7. These holes 7 and 8 serve a purpose to be presently described, and it may be noted that in the embodiment shown, eight holes are provided in each of the flanges.

Disposed adjacent the inner face of the flange 4 is a flat ring 9 made of a rigid material such as steel and having eight holes 10 therein, which are spaced circumferentially to correspond with the spacing of the holes 7 and are aligned axially therewith, each of the holes 10 having a conical wall, for a purpose to be presently described.

Disposed adjacent the inner face of the flange 6 is a flat ring 11 made of a rigid material such as steel and having eight holes 12 therein, which are spaced circumferentially to correspond with the spacing of the holes 8 and are aligned axially therewith, each of the holes 12 having a conical wall, for a purpose to be presently described.

The coupling further comprises a pair of axially spaced drive rings 13 and 14, made of a rigid material such as steel, these rings being of identical construction.

The ring 13 is provided adjacent its periphery with eight holes 15, spaced circumferentially to correspond with the spacing of the holes 7 and 8, and in axial alignment with the latter, it being noted that only the alternate holes in the ring are threaded. At each side of the ring 13 at the location of each hole 15, the ring is provided with an annular recess having a conical sidewall 16.

The ring 14 is also provided adjacent it periphery with eight holes 17, spaced circumferentially to correspond with the spacing of the holes 15, and in axial alignment with the latter, it being noted that only the alternate holes in the ring 14 are threaded, and that these threaded holes are staggered in rela tion to the threaded holes 15 in the ring 13. At each side of the ring 14, at the location of each hole 17, the ring is provided with an annular recess having a conical sidewall 18.

The coupling further comprises three axially spaced cushion rings 19, 20 and 21, made of a resilient material, such, for example, as Neoprene, and of identical construction, the ring 19 being interposed between the ring 9 and the ring 13, the ring 20 being interposed between the rings 13 and 14, and the ring 21 being interposed between the ring 14 and the ring 11.

The ring 19 is provided adjacent its periphery with eight holes 22, spaced circumferentially to correspond with the spacing of the holes 7 and in axial alignment with the latter. At each side of the ring 19, at the location of each hole 22, the ring is provided with a conical extension 23, the conical extensions 23 at one side of the ring being seated'in the conical recesses 10 of the ring 9, and the conical extensions 23 at the other side of the ring being seated in the conical recesses 16in one side of the ring 13.

The ring 20 is provided adjacent its periphery with eight holes 24, spaced circumferentially to correspond with the spacing of the holes 22 and in axial alignment with the latter. At each side of the ring 20, at the location of each hole 24, the ring is provided with conical extensions 25, the conical extensions 25 at one side of the ring being seated in the conical recesses 16 in one side of the ring 13, and the conical extensions 25 at the other side of the ring being seated in the conical recesses 18 in one side of the ring 14.

The ring 21 is provided adjacent its periphery with eight holes 26, spaced circumferentially to correspond with the spacing of the holes 22 and 24 and in axial alignment with the latter. At each side of the ring 21, at the location of each hole 26, the ring is provided with conical extensions 27, the conical extensions 27 at one side of the ring being seated in the conical recesses 18 in one side of the ring 14, and the conical extensions 27 at the other side of the ring being seated in the conical recesses 12 in the ring 11.

The coupling further comprises two sets of cap screws or studs, for assembling the parts of the coupling together. One set of such screws or studs, consisting of four screws, is designated by reference numeral 28, and the other set of four is designated by reference numeral 29.

The screws 28 are passed through the aligned holes or openings 7, 22, unthreaded holes 15, and holes 24, and threaded into the threaded holes 17 in the ring 14.

The screws 29 are passed through the aligned holes or openings 8, 26, unthreaded holes 17, and holes 24, and threaded into the threaded holes 15 in the ring 13.

In thus assembling the parts of the coupling, the resilient rings 19, 20 and 21 are compressed to an extent dependent on the required torque carrying capacity of the coupling. The torque-carrying capacity of the coupling, in other words, is a function of the degree of compression of the resilient or cushion rings.

In normal operation, the shafts 1 and 2 are axially aligned, and no undue stresses or strains are imposed on the coupling.

When a force angular to the axis of the coupling is applied to the coupling, as indicated by the arrows AA in FIG. 1, the cap screws or studs 29 exert a force on the resilient material of the cushion ring 20, as indicated by the arrow B, and the cap screws or studs 28 will exert an opposing force on the ring 20, as indicated by the arrow C. The ring 20 will thus be compressed in its upper portion, that is to say, the portion above the axis of the coupling, and the portions of the rings 19 and 21 below this axis will be compressed. When a similar force angular to the axis of the coupling, but in a direction opposite to that indicated by the arrows AA, is applied to the Coupling, the portions of the rings 19, 20 and 21 other than those referred to above, will be compressed. These deflective forces and compression of the ring result from misalignment of the shafts 1 and 2.

Thus, at no time, is the resilient material of the cushion rings 19, 20 and 21 under tension or stretch, but, rather, any deflec tion of the coupling, as described, tends to compress the resilient material. In deflecting a prototype coupling under a hydraulic press to an angle of 170, the coupling, upon release of the pressure, returned immediately to its normal or straight condition. This is a particularly important advantage of the coupling of this invention.

The conical extensions or projections on the cushion rings 19, 20 and 21, which extend into the conical recesses provided therefor, are supported internally or at their radially inward portions by the cap screws 28 and 29, and are trapped in the conical recesses by the pressure between drive rings 13 and 14, and between at 9 and 11 and the drive rings, so that the material constituting these conical extension or projections is under compression where the torque is being applied, and cannot be distorted.

The torque-carrying capacity of the coupling is greater where conical extensions are employed at all connecting points, eight points in this instance, but it is to be understood that conical extensions need not be employed at all such points,and that a lesser number of extensions may be employed, depending on convenience or torque requirements.

The rings 9 and 11 are provided for the purpose of obviating the need for making conical recesses or indentations in the flanges 4 and 6, corresponding to the conical recesses and 12 in these rings. This also accomplishes the purpose of enabling the use of resilient rings 19, and 21, which are identical construction, and thus interchangeable.

In the modified from of coupling shown in FIGS. 4, 5 and 6, the flange 4 has disposed adjacent its inner face a flat ring 30 made of a rigid material such as steel and having eight holes 31 therein, which are spaced circumferentially to correspond with the spacing of the holes 7 and are aligned axially therewith.

The ring 30 is provided on its inner face, in the areas of said face adjacent the holes 31, with radially extending grooves 32 of channel-shape cross section, each having beveled or inclined sides or edges 33 and 34.

The flange 6 has disposed adjacent its inner face a flat ring 35 made of a rigid material such as steel and having eight holes 36 therein which are spaced circumferentially to correspond with the spacing of the holes 8 and are aligned axially therewith.

The ring 35 is provided on its inner face, in the areas of said face adjacent the holes 36, with radially extending grooves 37 of channel-shaped cross section, each having beveled or inclined sides or edges 38 and 39.

The grooves 32 and 37 serve the same purpose, from a func-,

tional viewpoint, as the conical holes 10 and 12 of the coupling shown in FIG. 1.

The coupling further comprises a pair of axially spaced drive rings 40 and 41 made of a rigid material such as steel, and of identical construction.

The ring 40 is provided with eight holes 42, spaced circumferentially to correspond with the spacing of the holes 7 and 8, and in axial alignment with the latter, it being noted that only the alternate holes in the ring are threaded. At each side of the ring 40, at the location of each hole 42, the ring is provided with radially extending grooves 43 of channel-shape cross section, each having beveled or inclined sides or edges 44 and 45.

The ring 41 is also provided with eight holes 46 spaced circumferentially to correspond with the spacing of the holes 42, and in axial alignment with the latter, it being noted that only the alternate holes in the ring 41 are threaded, and that these threaded holes are staggered in relation to the threaded holes- 42in the ring 40. At each side of the ring 41, at the location of each hole 46, the ring is provided with radially extending grooves 47 of channel-shape cross section, each having beveled or inclined sides 48 and 49.

The'coupling further comprises three axially spaced cushion rings 50, 51 and 52, made of a resilient material, such, for example, as Neoprene, and of identical construction, the ring 50 being interposed between the ring 30 and the ring 40, the ring 51 being interposed between the rings 40 and 41, and the ring 52 being interposed between the ring 41 and the ring 35.

The ring 50 is provided adjacent its periphery with eight holes 53 spaced circumferentially to correspond with the spacing of the holes 7 and in axial alignment with the latter. At each sideof the ring 50, at the location of each hole 53, the ring is provided with a radially extending ribs 54 having inclined sides or edges 55 and 56, the ribs 54 at one side of the ring being seated in the grooves 32 of the ring 30, and the ribs 54 at the other side of the ring being seated in the grooves 43 in one side of the ring 40.

The ring 51 is provided with eight holes 57 spaced circumferentially to correspond with the spacing of the holes 53 and in axial alignment with the latter. At each side of the ring 51, at the location of each hole 57, the ring is provided with radially extending ribs 58 having inclined sides or edges 59 and 60, the ribs 58 at one side of the ring being seated in the grooves 43 in one side of the ring 40, and the ribs 58 at the other side of the ring being seated in the grooves 47 of the ring 41.

The ring 52 is provided with eight holes 61, spaced circumferentially to correspond with the spacing of the holes 53 and 57 and in axial alignment with the latter. At each side of the ring 52, at the location of each hole 61, the ring is provided with radially extending ribs 62 having inclined sides or edges 63 and 64, the ribs 62 at one side of the ring being seated in the grooves 47 or the ring 41, and the ribs 62 at the other side of the ring being seated in the grooves 37 of the ring 35.

The manner of assembling the parts of the coupling is similar to that described with reference to FlGs. 1, 2 and 3, and the grooves and ribs of the rings function in a manner similar to the conical seats and extensions of the coupling shown in FIGS. 1,2 and 3.

In the modified form of coupling shown in FIGS. 7, 8 and 9, the flange 4 has disposed adjacent its inner face a flat ring 65 made of a rigid material such as steel and having eight holes 66 therein which are spaced circumferentially to correspond with the spacing of the holes 7 and are aligned axially therewith.

The ring 65 is provided on its inner face in the areas of said face adjacent the holes 66 with radially extending grooves 67 having bottoms of arcuate cross section.

The flange 6 has disposed adjacent its inner face a flat ring 68 made of a rigid material such as steel and having eight holes 69 therein which are spaced circumferentially to correspond with the spacing of the holes 8 and are aligned axially therewith.

The ring 68 is provided on its inner face, in the areas of said face adjacent the holes 69, with radially extending grooves 70 having bottoms of arcuate cross section.

The grooves 67 and 70 serve the same purpose, from a fu nctional view point, as the conical holes 10 and 12 of the coupling shown in H6. 1.

The coupling further comprises a pair of axially spaced drive rings 71 and 72 made of a rigid material such as steel, and of identical construction.

The ring 71 is provided with eight holes 73, spaced circumferentially to correspond with the spacing of the holes 7 and 8, and in axial alignment with the latter, it being noted that only the alternate holes in the ring are threaded. At each side of the ring 71, at the location of each hole 73, the ring is provided with radially extending grooves 74 having bottoms of arcuate cross section.

The ring 72 is also provided with eight holes 75 spaced circumferentially to correspond with the spacing of the holes 73, and in axial alignment with the latter, it being noted that only the alternate holes in the ring 72 are threaded, and that these threaded holes are in staggered relation to the threaded holes 73 in the ring 71. At each side of the ring 72, at the location of each hole 75, the ring is provided with radially extending grooves 76 having bottoms of arcuate cross section.

The coupling further comprises three axially spaced cushion rings 77, 78 and 79, made of a resilient material, such, for example, as Neoprene, and of identical construction, the ring 77 being interposed between the ring 65 and the ring 71, the ring 78 being interposed between the rings 71 and 72, and the ring 79 being interposed between the ring 72 and the ring 68.

The ring 77 is provided with eight holes 80 spaced circumferentially to correspond with the spacing of the holes 7 and in axial alignment with the latter. At each side of the ring 77, at the location of each hole 80, the ring is provided with radially extending ribs 81 having faces of arcuate cross section, the ribs 81 at one side of the ring being'seated in the grooves 67 of the ring 65, and the ribs 81 at the other side of the ring being seated in the grooves 74 in one side of the ring 71.

The ring 78 is provided with eight holes 82, spaced circumferentially to correspond with the spacing of the holes 80 and in axial alignment with the latter. At each side of the ring 78, at the location of each hole 82, the ring is provided with radially extending ribs 83 having faces of arcuate cross section, the ribs 83 at one side of the ring being seated in the grooves 74 in one side of the ring 71, and the ribs 83 at the other side of the ring being seated in the grooves 76 of the ring 72.

The ring 79 is provided with eight holes 84 spaced circum ferentially to correspond with the spacing of the holes 80 and 82 and in axial alignment with the latter. At each side of the ring 79, at the location of each hole 84, the ring is provided with radially extending ribs 85 having faces of arcuate cross section, the ribs 85 at one side of the ring being seated in the grooves 76 of the ring 72, and the ribs 85 at the other side of the ring being seated in the grooves 70 in the ring 68.

The manner of assembling the parts of the coupling is similar to that described with reference to FIGS. 1, 2 and 3, and the grooves and ribs of the rings function in a manner similar to the conical seats and extensions of the coupling shown in Figs. 1, 2 and 3.

Referring now to FIGS. 10 and 11 of the drawings, a coupling similar to that shown in FIG. 1 is illustrated, but in which a flange 4a is used, having a collar or hub 3a, which extends into the coupling, that is to say, the collar or hub is reversed in its position, as compared with its position as shown in FIG. 1.

This creates several advantages, which may be explained as follows:

Since the flange 4a is not a standard marine fitting, as is the flange 4 of FIG. 1, but is a part manufactured expressly for, and furnished with, the coupling, it can be made or formed on its inner face with the conical walls 10a corresponding to the conical walls 10 shown in FIG. 1 for receiving the conical extensions 23 of the ring 19, thereby eliminating the use of the ring 9.

Similarly, the flange 40 can be made or formed on its inner face with radially extending grooves of channel cross section, each having beveled or inclined sides or edges, and corresponding to the grooves 32 in FIG. 4, for receiving the ribs 54 of the ring 50, thereby eliminating the use of the ring 30.

In the same manner, the flange 40 can be made or formed on its inner face with radially extending grooves having bottoms of arcuate cross section, and corresponding to the grooves 67 in FIG. 7, for receiving the ribs 81 of the ring 77, thereby eliminating the use ofthe ring 65.

The greatest advantage of thus reversing the position of the collar or hub 30, however, is that it enables the coupling to be installed on the shaft 1 without having to shorten this shaft excessively, and without having to remill a new keyway 86 therein, as would be necessary where the portion of the shaft which is removed contains the keyway.

As shown in FIGs. 10 and 11, the flange 4a is drilled radially and tapped for the reception ofa setscrew (not shown), which bears against the key 87, thereby locking the flange 4a to the shaft 1, and, at the same time, locking the key 87 into the keyway 86.

Although the invention has been described particularly with reference to its use as a coupling for connecting a marine engine to a propeller shaft, it will be understood that it may be used for other applications in which a resilient coupling is desired or necessary.

It is to further understood that the forms of my invention, herewith shown and described, are to be taken as preferred examples of the same, and that various changes may be made in the shape, size and arrangement of parts thereof, without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. In a resilient coupling of the character described, a pair of flanged collars, a plurality of axially spaced rings of a resilient material disposed between the flanges of said collars, axially spaced rings of a rigid material interposed between said firstnamed rings, and means for drawing said collars toward each other, whereby to maintain said rings of resilient material under compression.

2. A coupling, as defined in claim 1, wherein said rings of resilient material are provided on their faces with circumferentially spaced conical extensions, and said rings of rigid material are provided on their faces with conical seats in which said conical extensions are received.

3. A coupling, as defined in claim 1, wherein said rings of resilient material are provided on their faces with circumferentially spaced radially extending ribs, and said rings of rigid material are provided on their faces with circumferentially spaced radially extending grooves in which said ribs are seated.

4. A coupling, as defined in claim 3, wherein said ribs have peripheral surfaces of arcuate cross section, and said grooves have bottoms of arcuate cross section.

5. In a resilient coupling of the character described, a pair of flanged collars having circumferentially spaced holes adjacent the peripheries of the flanges thereof, a plurality of axially spaced rings of resilient material disposed between the flanges of said collars and having circumferentially spaced holes in axial alignment with the holes in said flanges, axially spaced rings of a rigid material interposed between said first-named rings and having circumferentially spaced holes in axial alignment with the holes in said flanges and first-named rings, certain of said holes in said rings of rigid material being threaded, screw bolts extending through the flange of one of said collars and through holes in said rings and threaded into the threaded openings in that ring of rigid material which is most remote from the flange of said one collar, and screw bolts extending through the flange of the other of said collars and through holes in said rings, and threaded into the threaded openings in that ring of rigid material which is most remote from the flange of the other of said collars.

6. A coupling, as defined in claim 5, wherein said rings of resilient material are provided on their faces with conical extensions which surround the holes in said rings, and said rings of rigid material are provided on their faces with conical seats in which said conical extensions are received.

7. A coupling, as defined in claim 5, wherein said rings of resilient material are provided on their faces with radially extending ribs which intersect the axes of the holes in said rings, and said rings of rigid material are provided on their faces with circumferentially spaced grooves in which said ribs are seated.

8. A coupling, as defined in claim 7, wherein said ribs have peripheral surfaces of arcuate cross section, and said grooves have bottoms of arcuate cross section.

9. In a resilient coupling of the character described, a pair of flanged collars, a plurality of axially spaced rings of resilient material disposed between the flanges of said collars, axially spaced rings of rigid material interposed between said firstnamed rings, and means for drawing said collars toward each other, whereby to maintain said rings of resilient material under compression, the collar of one of said flanged collars extending into said coupling, thereby occupying space enclosed by said rings.

10. A coupling, as defined in claim 9, including a shaft having a portion extending into said coupling, and to which said last-named collar is secured.

11. A coupling, as defined in claim 10, wherein the portion of said shaft which extends into said coupling is provided with 

1. In a resilient coupling of the character described, a pair of flanged collars, a plurality of axially spaced rings of a resilient material disposed between the flanges of said collars, axially spaced rings of a rigid material interposed between said first-named rings, and means for drawing said collars toward each other, whereby to maintain said rings of resilient material under compression.
 2. A coupling, as defined in claim 1, wherein said rings of resilient material are provided on their faces with circumferentially spaced conical extensions, and said rings of rigid material are provided on their faces with conical seats in which said conical extensions are received.
 3. A coupling, as defined in claim 1, wherein said rings of resilient material are provided on their faces with circumferentially spaced radially extending ribs, and said rings of rigid material are provided on their faces with circumferentially spaceD radially extending grooves in which said ribs are seated.
 4. A coupling, as defined in claim 3, wherein said ribs have peripheral surfaces of arcuate cross section, and said grooves have bottoms of arcuate cross section.
 5. In a resilient coupling of the character described, a pair of flanged collars having circumferentially spaced holes adjacent the peripheries of the flanges thereof, a plurality of axially spaced rings of resilient material disposed between the flanges of said collars and having circumferentially spaced holes in axial alignment with the holes in said flanges, axially spaced rings of a rigid material interposed between said first-named rings and having circumferentially spaced holes in axial alignment with the holes in said flanges and first-named rings, certain of said holes in said rings of rigid material being threaded, screw bolts extending through the flange of one of said collars and through holes in said rings and threaded into the threaded openings in that ring of rigid material which is most remote from the flange of said one collar, and screw bolts extending through the flange of the other of said collars and through holes in said rings, and threaded into the threaded openings in that ring of rigid material which is most remote from the flange of the other of said collars.
 6. A coupling, as defined in claim 5, wherein said rings of resilient material are provided on their faces with conical extensions which surround the holes in said rings, and said rings of rigid material are provided on their faces with conical seats in which said conical extensions are received.
 7. A coupling, as defined in claim 5, wherein said rings of resilient material are provided on their faces with radially extending ribs which intersect the axes of the holes in said rings, and said rings of rigid material are provided on their faces with circumferentially spaced grooves in which said ribs are seated.
 8. A coupling, as defined in claim 7, wherein said ribs have peripheral surfaces of arcuate cross section, and said grooves have bottoms of arcuate cross section.
 9. In a resilient coupling of the character described, a pair of flanged collars, a plurality of axially spaced rings of resilient material disposed between the flanges of said collars, axially spaced rings of rigid material interposed between said first-named rings, and means for drawing said collars toward each other, whereby to maintain said rings of resilient material under compression, the collar of one of said flanged collars extending into said coupling, thereby occupying space enclosed by said rings.
 10. A coupling, as defined in claim 9, including a shaft having a portion extending into said coupling, and to which said last-named collar is secured.
 11. A coupling, as defined in claim 10, wherein the portion of said shaft which extends into said coupling is provided with a keyway having a key therein, and the flange of said last-named flanged collar is provided with a radially extending tapped hole having a set screw therein which bears against said key.
 12. A coupling, as defined in claim 11, wherein the flange of said last-named flanged collar is provided on its inner face with recesses adapted to receive portions of one of said rings of resilient material. 